Keep your promises and be true to your word .

This hadith is about fulfilling vows that were made in the pre-Islamic period. Umar had vowed to perform I'tikaf in Al Masjid al Haram, and Allah's Messenger told him to fulfill his vow. This teaches us that we should always keep our promises and be true to our word, no matter how long ago it was made. We should also remember that even if something was done before Islam, it is still important for us as Muslims today to uphold those values and commitments. It is also important for us not only to make promises but also follow through with them so that we can be trusted by others.