Sunan Ibn Majah
2129
Sahih+3

It was narrated that 'Umar bin Khattab said:"I made a vow during the Ignorance period and I asked the Prophet (ﷺ) (about it) after I became Muslim. He told me to fulfill my vow

SahihAl-Albani
SahihMuhammad Fouad Abd al-Baqi