question #1 Sahih al-Bukhari 2032, Book 33, Hadith 7 : What is the significance of fulfilling vows made before embracing Islam?

`Umar asked the Prophet (ﷺ) “I vowed in the Pre-Islamic period of ignorance to stay in I`tikaf for one
night in Al-Masjid al-Haram.” The Prophet (ﷺ) said to him, “Fulfill your vow.”