'Mercy' in the Bible

O give praise to the Lord, for he is good: for his mercy is unchanging for ever.

And with them Heman and Jeduthun, and the rest who were marked out by name to give praise to the Lord, for his mercy is unchanging for ever;

I will be to him a father and he will be to me a son; and I will not take my mercy away from him as I took it from him who was before you;