Muslims in Muslim-majority countries should enhance the kafâlah system (care for orphans) to attain all of the benefits of legal adoption, while complying with the spirit and letter of the Sharia in this regard. Wherever a kafâlah system is not available, Muslims may legally adopt children, to fulfill the obvious necessity, with the following guidelines:
-Maintaining transparency and affording the children the right to know their lineage, ethnic and national origins. This can be done with open adoption.
-Keeping the family names of the children whenever legally possible. When not, the children may be given the last name of the adoptive family.
-Maintaining all of the shar‘i (Islamically legal) constraints, such as the rules of mingling and inheritance, to the best of the involved parties’ capacity, while showing flexibility in relieving these constraints whenever possible with concessions and valid legal devices that are not in conflict with the objectives of al-Shâriʽa.
One of the ways those constraints may be relieved is by breastfeeding those orphans. If an infant lost his mother, another woman could nurse him, and he will be a member of her family forever. According to a study published by The Journal of the American Board of Family Medicine, breastfeeding the adopted child is recommended and possible for women who did not give birth. Also, note that, according to the majority of scholars, the legally prohibitive breastfeeding is whatever milk enters the throat, whether by suckling or through drenching (pouring milk into the throat), and whether it was pure or mixed, as long as it is not completely absorbed into the other substance.
Breastfeeding an infant under the age of two will result in him being part of the ‘milk-family’ by consensus. However, some of the orphans who need homes and families may be past the age cutoff, which is two years according to the vast majority, with some slight variations (Abu Ḥaneefah: 30 months; Mâlik: 26 months). To the vast majority, those orphans may not be breastfed to establish maḥramiyyah (legal prohibition). There is, however, an authentic hadith reported by Muslim that the Prophet (pbuh) said to the wife of Abu Ḥudhayfah concerning Sâlim, the freed slave of Abu Ḥudhayfah: “Breastfeed him, then you will become his maḥram.” This happened after the prohibition of adoption. Sâlim was their adoptee, and had nowhere else to go, and he was a young adult, so the Prophet (pbuh) allowed her to do that for this special condition.
Some of the scholars considered the breastfeeding of one older than two prohibitive, and that is the position of Abdullah ibn az-Zubayr, ‘Urwah, Muhammad ibn al-Qâsim, ‘Aṭâ’, and was most defended by Imam Ibn Ḥâzm. Before that, it was adopted by ‘Â’ishah – may Allah be pleased with her. However, Umm Salamah and all other wives of the Prophet (pbuh) (except Ḥafsah, as reported by aṭ-Ṭabari) refused that position and told ‘Â’ishah, “By Allah, we do not know whether that was a special concession granted by the Prophet (pbuh) to Sâlim, exclusive (to him) of the people” (Abu Dawud). The majority followed the reasoning of Umm Salamah and the other wives of the Prophet (pbuh) and considered this ruling to be exclusive for Sâlim or abrogated by the specification of the two year term.
Imams Ibn Taymiyyah and Ibn al-Qayyim took a middle position. They considered it prohibitive only when there is a need similar to that of Abu Hudhayfah’s family. Although this position is a minority one, it has some validity, and it may also ease the suffering of many Muslim children by facilitating their foster caring by surrogate Muslim families. This is not regarded as a trick or pretense, rather it is a legitimate shar‘i concession. And while it is commendable for Muslims to be wary of positions that are in conflict with the agreement of the four imams, this aversion should not completely rule out the possibility that the truth may be outside of their agreement, but merely serve as a warning for mujtahideen (Muslim jurists) to proceed with caution and for non-mujtahideen to stop. Even if we consider an opinion weak, it may sometimes be adopted by the verifying scholars to relieve some hardship, given that it meets some conditions as described by the author of Marâqi as-Su‘ood in the following verses:
وكَوْنِهِ يُلْــجى إليهِ الضَّرَرُ — إنْ كانَ لَمْ يَشْتَــدّ فِيهِ الخَوَرُ
وثَبَتَ العَــزْوُ وقَـدْ تَحَقَّقَا — ضُرّاً مَن الضُّرُّ بِهِ تَعَلَّــــقَا
Finally, because the pressing need or necessity may compel people to act upon such [weak positions] if they are not too weak, and their attribution [to a mujtahid] was established, and the one under duress is certain of their necessity.
Source: Dr. Hatem’s Facebook Post
 It is not clear from the hadith how Salim was given the milk. Imam Nawawi said, “Al-Qadhi said, ‘Perhaps she squeezed the milk out [into a cup] and then he drank it without touching her breasts nor her skin.’ This statement of Al-Qadhi is good.” More info