My question is about al-Nazer (vow). I was expecting a child, I promised to slaughter 10 sheep if my child would be born without any health problems and distribute them among the poor. My child was born fine thanks god. My wife and I slaughtered 2 sheep so far. We live in the United States. Is not slaughtering the 10 sheep at the same a problem. What should be done? Can I give the cost of the remaining sheep to the poor or must slaughter the sheep. How much time do I have to fulfill my Nazr.

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

If you intended (vowed) to slaughter ten sheep directly after your wife's delivery; i.e., in a fixed period of time, you should honor your vow; otherwise, you are sinful. In other words, if you slaughtered two sheep only, you should slaughter the other sheep (i.e. eight) at once. But, if your intention was to slaughter ten sheep in an unfixed time, then there would be no blame on you to do accordingly although it is better to fulfill your vow directly.

Also, it is not permitted to pay the value of the sheep; i.e., you have to slaughter.

Here, we add that if your intention was just a "promise not a vow" to slaughter ten sheep – as stated in your question – then there would be no blame on you to fulfill it or not, but it is recommendable.

For more benefit on fulfilling a vow and whether or not it requires repetition, please refer to Fataawa 8800, 1125, 29377, 367117, 119549, 138168 and 249157.

Allah knows best.