John Gill Commentary Joshua 1:17

"According as we hearkened unto Moses in all things, so will we hearken unto thee: only Jehovah thy God be with thee, as he was with Moses." — Joshua 1:17 (ASV)

According as we have hearkened to Moses in all things, so
we will hearken to you
Not right or wrong, but in all things that were according to the laws and will of God made known to them; and particularly it may refer to the above affair, which was settled between Moses and them, to whom they then hearkened, and now promise to confirm the same, and hearken to whatever orders and instructions Joshua should give them relative to it, based on the agreed-upon plan:

only the Lord your God be with you, as he was with Moses ;
which is not mentioned as a condition of their obedience to him, but rather as a reason of it, and as an encouraging motive to it; for, according to Kimchi, the true sense and meaning is, ``for the Lord your God will be with you, as he was with Moses;'' so Noldius renders it, ``seeing the Lord your God is with you.''