It is narrated from Sayyidah Aishah (may Allah be pleased with her) that the Prophet (peace and blessings be upon him) ordered Sayyidah Sahlah bint Suhayl (may Allah be pleased with her) to suckle Salim, so that the unease in the heart of Sayyiduna Abu Hudhayfah (may Allah be pleased with him) would go away.
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 6345