וַֽיְהִי֙ כִּֽי־חָזַ֣ק יִשְׂרָאֵ֔ל וַיָּ֥שֶׂם אֶת־הַֽכְּנַעֲנִ֖י לָמַ֑ס וְהוֹרֵ֖ישׁ לֹ֥א הוֹרִישֽׁוֹ׃ (ס)
And it came to pass, when Israel was waxen strong, that they put the Canaanites to task-work, but did in no wise drive them out.
Read midrashic interpretation of Judges 1:28: and classical rabbinic exegesis.