Rashi

כי ידין ה' עמו — This means, when He will sentence them to all these sufferings that are mentioned concerning them. The phrase has the same meaning as (Job 36:31) “For by them ידין nations”, i.e. He will chastise the nations. — This word כי has not the meaning of “because”, giving the reason for the preceding statements, but it is an expression (a particle) beginning a new a statement, as (Leviticus 25:2) “When (וכי) ye will come into the land” (cf. Rashi on that passage). The meaning is: When these judgment will come upon them, and the Lord will bethink Himself concerning His servants to have mercy on them again.
יתנחם HE WILL REPENT — This is an expression for changing one’s mind whether for good or for evil.
כי יראה כי אזלת יד WHEN HE SEETH THAT THEIR POWER IS GOING ON — i.e. when He sees that the power of the enemies is constantly becoming exceedingly stronger over them,ואפס AND THERE IS NOT among them עצור ועזוב.
עצור is one who is saved by a עוצר (a “restrainer”) and ruler who would restrain them,
עזוב means one saved by an עוזב. Now an עוצר is a ruler who keeps the people in check that they should not march in scattered groups when they go into war against the enemy, maintenue in old French, (Engl = maintainer). Consequently עצור (the passive) is one who is saved through the restraint of the ruler. עזוב is one who is strengthened, as (Nehemiah 3:8) “and they fortified (ויעזבו) Jerusalem unto the broad wall”; (Jer. 49:25) “How is this city of praise not helped (עזובה)!”. In old French anforcede, (English = fortified).