New Revised Standard Version
Therefore, O LORD, God of Israel, keep for your servant my father David that which you promised him, saying, ‘There shall never fail you a successor before me to sit on the throne of Israel, if only your children look to their way, to walk before me as you have walked before me.’

Contemporary English Version
LORD God of Israel, you promised my father that someone from his family would always be king of Israel, if they do their best to obey you, just as he did.

New American Bible
And now, LORD, God of Israel, keep toward your servant, David my father, what you promised: There shall never be wanting someone from your line to sit before me on the throne of Israel, provided that your descendants keep to their way, walking before me as you have.

Douay-Rheims Bible
Now, therefore, O Lord God of Israel, keep with thy servant David, my father, what thou hast spoken to him, saying: There shall not be taken away of thee a man in my sight, to sit on the throne of Israel: yet so that thy children take heed to their way, that they walk before me as thou hast walked in my sight.

Now, therefore, O Lord God of Israel, keep with thy servant David, my father, what thou hast spoken to him, saying: There shall not be taken away of thee a man in my sight, to sit on the throne of Israel: yet so that thy children take heed to their way, that they walk before me as thou hast walked in my sight.

keep with thy

1 Kings 2:4 That the Lord may confirm his words, which he hath spoken of me, saying: If thy children shall take heed to their ways, and shall walk before me in truth, with all their heart, and with all their soul, there shall not be taken away from thee a man on the throne of Israel.

2 Samuel 7:27-29 Because thou, O Lord of hosts, God of Israel, hast revealed to the ear of thy servant, saying: I will build thee a house: therefore hath thy servant found in his heart to pray this prayer to thee. . . .

1 Chronicles 17:23-27 Now therefore, O Lord, let the word which thou hast spoken to thy servant, and concerning his house, be established for ever, and do as thou hast said. . . .

Luke 1:68-72 Blessed be the Lord God of Israel: because he hath visited and wrought the redemption of his people. . . .

There shall not, etc.

so that [heb] only if

1 Kings 2:4 That the Lord may confirm his words, which he hath spoken of me, saying: If thy children shall take heed to their ways, and shall walk before me in truth, with all their heart, and with all their soul, there shall not be taken away from thee a man on the throne of Israel.

1 Kings 9:4-6 And if thou wilt walk before me, as thy father walked, in simplicity of heart, and in uprightness: and wilt do all that I have commanded thee, and wilt keep my ordinances, and my judgments, . . .

1 Chronicles 28:9 And thou my son Solomon, know the God of thy father, and serve him with a perfect heart, and a willing mind: for the Lord searcheth all hearts, and understandeth all the thoughts of minds. If thou seek him, thou shalt find him: but if thou forsake him, he will cast thee off for ever.

2 Chronicles 6:16,17 Now then, O Lord God of Israel, fulfil to thy servant David my father, whatsoever thou hast promised him, saying: There shall not fail thee a man in my sight, to sit upon the throne of Israel: yet so that thy children take heed to their ways, and walk in my law, as thou hast walked before me. . . .