Verses with the word heir in the Old Testament (8 verses):

Genesis 15:3
And Abram said, Behold, to me thou hast given no seed: and, lo, one born in my house is mine heir.

Genesis 15:4
And, behold, the word of the LORD came unto him, saying, This shall not be thine heir; but he that shall come forth out of thine own bowels shall be thine heir.

Genesis 21:10
Wherefore she said unto Abraham, Cast out this bondwoman and her son: for the son of this bondwoman shall not be heir with my son, even with Isaac.

2 Samuel 14:7
And, behold, the whole family is risen against thine handmaid, and they said, Deliver him that smote his brother, that we may kill him, for the life of his brother whom he slew; and we will destroy the heir also: and so they shall quench my coal which is left, and shall not leave to my husband neither name nor remainder upon the earth.

Proverbs 30:23
For an odious woman when she is married; and an handmaid that is heir to her mistress.

Jeremiah 49:1
Concerning the Ammonites, thus saith the LORD; Hath Israel no sons? hath he no heir? why then doth their king inherit Gad, and his people dwell in his cities?

Jeremiah 49:2
Therefore, behold, the days come, saith the LORD, that I will cause an alarm of war to be heard in Rabbah of the Ammonites; and it shall be a desolate heap, and her daughters shall be burned with fire: then shall Israel be heir unto them that were his heirs, saith the LORD.

Micah 1:15
Yet will I bring an heir unto thee, O inhabitant of Mareshah: he shall come unto Adullam the glory of Israel.