Isaiah 41:14

אַל־תִּירְאִי תּוֹלַעַת יַעֲקֹב מְתֵי יִשְׂרָאֵל אֲנִי עֲזַרְתִּיךְ נְאֻם־יְהוָה וְגֹאֲלֵךְ קְדוֹשׁ יִשְׂרָאֵל׃ 

14 Do not be afraid, O worm Jacob, O little band of Israel; I will help you," a burden of the LORD. Your redeemer is the Holy One of Israel.

אַל־תִּירְאִי תּוֹלַעַת יַעֲקֹב   Do not be afraid, O worm Jacob,  Once again אַל־תִּירְאִי for an immediate prohibition (see verse 10). The fem. singular occurs here because תּוֹלַעַת "worm" is feminine. The Lord uses "worm" in the sense of a small, helpless thing. It’s not derogatory, but it is meant to wake the people up so that they would see themselves in the context of their place in the universe, with all the terrors of the devil and his demons arrayed against them. An Mp note mentions that תּוֹלַעַת יַעֲקֹב "O worm Jacob" only occurs here.

מְתֵי יִשְׂרָאֵל  O little band of Israel; The vocalization of מְתֵי is uncertain. In essence, a מַת is a "man," but the plural in parallel context with "worm" indicates a small band of men.

אֲנִי עֲזַרְתִּיךְ נְאֻם־יְהוָה   I will help you," a burden of the LORD. Once again the Lord tells us he has helped us in the perfect tense (עֲזַרְתִּיךְ). The phrase "A burden of the LORD" (נְאֻם־יְהוָה) has been thoroughly examined by Prof. Paul Raabe of Concordia in his excellent commentary on Obadiah (p. 136). Generally this phrase (with some form of the divine name) introduces or concludes a prophetic utterance of the Lord. Raabe has counted 25 occurrences in Isaiah, of a total of 357 in all. All of these were spoken by a prophet, including one by Moses himself, except for one time when an angel speaks it in Gen. 22:16.

וְגֹאֲלֵךְ קְדוֹשׁ יִשְׂרָאֵל  Your redeemer is the Holy One of Israel.  A גֹאֵל is a kinsman-redeemer, a relative who would be a legal defender and protector of all of his family’s interests. This is the role that Boaz knew he had in the story of Ruth (Ruth 3:12). The breadth of the role is also expressed this way: “Deliver me...defend my cause and redeem me; preserve my life, according to your promise” (Psalm 119:153-154). The redeemer provided an heir if his brother or cousin died without one (Deuteronomy 25:5-10). He redeemed land if someone was forced to sell it outside the family, and he redeemed a family member sold into slavery. In certain circumstances he was also permitted to avenge a family member who was killed (Numbers 35:19-21). The Lord tells us that he himself is our Redeemer, the one who would redeem all Israel, just as he had when they were oppressed by the Egyptians (Exodus 6:6). To have God himself, the Holy One of Israel, as our redeemer, is to have the most certain promise of redemption possible. It is so certain that the Lord tends to speak in the past tense about it, as we have seen. This is not overconfidence, but Divine confidence. God knows what will happen, and we are safely in his basket.