Allah's Messenger ﷺ said, "The womb is a branch attached to the Most Merciful. Whoever maintains its ties, Allah maintains ties with him, and whoever severs it, Allah severs ties with him."
الله عن النبي ﷺ قال: الرحم شجنة، فمن وصلها وصلته، ومن قطعها قطعته.
Bukhari narrated it in al-Adab (5989) and Muslim in al-Birr wal-Silah wal-Adab (2555), both through the route of Muawiya bin Abu Muzarrid, from Yazid bin Ruman, from Urwa, from Ayesha, the wife of the Prophet ﷺ, who mentioned it, and the wording given here is Bukhari's. Muslim's wording is, "The womb-tie is suspended from the Throne, saying, 'Whoever maintains me, Allah will maintain him, and whoever severs me, Allah will sever him.'"