New Revised Standard Version
provided you diligently observe this entire commandment that I command you today, by loving the LORD your God and walking always in his ways—then you shall add three more cities to these three,

New American Bible
because you carefully observe this whole commandment which I give you today, loving the LORD, your God, and ever walking in his ways, then add three more cities to these three.

Douay-Rheims Bible
(Yet so, if thou keep his commandments, and do the things which I command thee this day, that thou love the Lord thy God, and walk in his ways at all times) thou shalt add to thee other three cities, and shalt double the number of the three cities aforesaid:

(Yet so, if thou keep his commandments, and do the things which I command thee this day, that thou love the Lord thy God, and walk in his ways at all times) thou shalt add to thee other three cities, and shalt double the number of the three cities aforesaid:

If thou shalt

Deuteronomy 11:22-25 For if you keep the commandments which I command you, and do them, to love the Lord your God, and walk in all his ways, cleaving unto him, . . .

Deuteronomy 12:32 What I command thee, that only do thou to the Lord: neither add any thing, nor diminish.

then shalt thou

Joshua 20:7,8 And they appointed Cedes in Galilee of mount Nephtali, and Sichem in mount Ephraim, and Cariath-Arbe, the same is Hebron in the mountain of Juda. . . .