It is narrated from Sayyiduna Abu al-Darda' (may Allah be pleased with him) that a man was ordered by his parents, or by one of them, to divorce his wife. He vowed that if he did so he would free a thousand slaves, or a hundred slaves, and pledged his wealth as an offering. Then he came to Abu al-Darda' (may Allah be pleased with him); (the narrator) mentioned that he prayed the Duha prayer, and then the man asked him. He said: Fulfil your vow and be kind to your parents, for I heard the Messenger of Allah (peace and blessings be upon him) say: "The father is the best, the middle, of the gates of Paradise." Now it is up to you whether you guard this gate or abandon it. This hadith has a sahih (authentic) chain of narration, but the two Shaykhs (Bukhari and Muslim) did not record it.