They have all gone out of the way - They have “declined” from the true path of piety and virtue.
They are together - They have at the same time; or they have equally become unprofitable. They are as one; they are joined, or united in this declension. The expression denotes union, or similarity.
Become unprofitable - This word in Hebrew means to become “putrid” and “offensive,” like fruit that is spoiled. In Arabic, it is applied to “milk” that becomes sour. Applied to moral subjects, it means to become corrupt and useless. They are of no value in regard to works of righteousness.
There is none ... - This is taken literally from the Hebrew.