Because the LORD was not able to bring this people into the land which he sware unto them, therefore he hath slain them in the wilderness.

He could not bring the people into the land for which he had sworn, therefore did he kill them in the wilderness.

Because Jehovah was not able to bring this people into the land that he had sworn unto them, he has therefore slain them in the wilderness.

From Jehovah's want of ability to bring in this people unto the land which He hath sworn to them, He doth slaughter them in the wilderness.

Because the Lord was not able to take this people into the land which he made an oath to give them, he sent destruction on them in the waste land.

'He was not able to lead the people into the land about which he had sworn. Therefore, he slew them in the wilderness.'

Quia absque potentia est Jehova, ut introducat populum istum in terram, quam juravit eis, ideo mactavit eos in deserto.

Because the Lord was not able to bring this people into the land which he sware unto them,.... That though he brought them out of Egypt, he was not able to bring them through the wilderness into Canaan; and that though he had wrought many signs and wonders for them, he could work no more, his power failed him, he had exhausted all his might, and could not perform the promise and oath he had made:
therefore he hath slain them in the wilderness; because he could not fulfil his word, and so made short work of it, destroying them all together, which Moses suggests would greatly reflect dishonour on him; and in this he shows, that he was more concerned for the glory of God than for his own.

Not able - His power was quite spent in bringing them out of Egypt, and could not finish the work he had begun and had sworn to do.