Allah, the Blessed and Exalted, says: "Mothers shall nurse their children for two full years; (this is) for one who wishes to complete the nursing." [Surah al-Baqarah: 233]
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الرضاع / Q15663
Sufyan narrated to us from Abdullah bin Dinar, who narrates from Ibn Umar (may Allah be pleased with them both) that he said: I heard Umar (may Allah be pleased with him) saying: There is no fosterage except in the first two years of childhood.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الرضاع / 15663
It is narrated from Yahya bin Sa'id (may Allah have mercy on him) that Abu Musa (may Allah be pleased with him) said about the nursing of an adult: I can only consider that it establishes prohibition. Ibn Mas'ud (may Allah be pleased with him) said: Consider carefully the ruling you are giving the man. Abu Musa (may Allah be pleased with him) said: Then what do you say? Ibn Mas'ud (may Allah be pleased with him) said: Fosterage is only what takes place within the two years. Abu Musa (may Allah be pleased with him) said: Do not ask me (about anything) as long as this learned scholar is among you.
Although this is mursal, it has supporting narrations (shawahid) from Ibn Mas'ud (may Allah be pleased with him).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الرضاع / 15664
It is narrated from Abdullah (bin Mas'ud) (may Allah be pleased with him): "Fosterage is only what takes place within the two years, and what grows the flesh and strengthens the bones." Yahya bin Sa'id narrated it with the same meaning from Abdullah bin Mas'ud (may Allah be pleased with him) as mursal, concerning the two years.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الرضاع / 15665
Ikrimah narrates from Sayyiduna Ibn Abbas (may Allah be pleased with them both): Whatever takes place within the two years establishes prohibition, even if it is a single suck; and if it is after the two years, it is nothing.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الرضاع / 15667
أَخْبَرَنَا أَبُو حَازِمٍ الْحَافِظُ، أنا أبو الْفَضْلُ بْنُ خُمَيْرَوَيْهِ، أنا أَحْمَدُ بْنُ نَجْدَةَ، نا سَعِيدُ بْنُ مَنْصُورٍ، نا سُفْيَانُ، عَنْ عَمْرِو بْنِ دِينَارٍ، عَنِ ابْنِ عَبَّاسٍ رَضِيَ اللهُ عَنْهُمَا قَالَ: " لَا رَضَاعَ إِلَّا مَا كَانَ فِي الْحَوْلَيْنِ " هَذَا هُوَ الصَّحِيحُ مَوْقُوفٌ.
Amr bin Dinar narrates from Ibn Abbas (may Allah be pleased with them both): Fosterage is only within the two years. What is correct is that this is mawquf (stopping at the Companion).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الرضاع / 15668
It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that the Prophet (peace and blessings be upon him) said: "Nursing does not establish prohibition except what takes place within the two years."
Abu Ahmad said: This is known (as narrated) by al-Haytham bin Jamil from Ibn Uyaynah with a connected chain (musnad), while others besides al-Haytham narrate it as mawquf on Ibn Abbas (may Allah be pleased with them both).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الرضاع / 15669
Dawud bin Abi Hind narrated to us from Ikrimah, who narrates from Ibn Abbas (may Allah be pleased with them both): When a woman gives birth to a child after nine months, she should nurse it for twenty-one months; if she gives birth after seven months, she should nurse it for twenty-three (23) months; and when she gives birth after six (6) months, she should nurse it for twenty-four (24) months, as Allah has said.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الرضاع / 15670