And say thou unto the people, Sanctify yourselves against to morrow,
and ye shall eat flesh: for ye have wept in the ears of the Lord, saying, Who shall give us flesh to eat?
for it was well with us in Egypt: therefore the Lord will give you flesh, and ye shall eat. 
Ye shall not eat one day, nor two days, nor five days, neither ten days, nor twenty days; 
But even a whole month, until it come out at your nostrils, and it be loathsome unto you:
because that ye have despised the Lord which is among you,
and have wept before him, saying, Why came we forth out of Egypt? Numbers 11:18-20

When we pray, our hearts must be right and our intentions must be clean and pure.
To pray for our own desires without a consideration of God’s will will not please God.
If you have ought in your heart or you haven’t been treating someone well,
get your heart right, then come back to the throne to offer your petition.
That’s what Jesus said to do:

Therefore if thou bring thy gift to the altar,
and there rememberest that thy brother hath ought against thee;
Leave there thy gift before the altar, and go thy way; first be reconciled to thy brother,
and then come and offer thy gift. Matthew 5:23-24

If you’re prayer is being hindered by something through no fault of your own,
rest assured, that the answer is on the way.