מַעְיַ֣ן גַּנִּ֔ים בְּאֵ֖ר מַ֣יִם חַיִּ֑ים וְנֹזְלִ֖ים מִן־לְבָנֽוֹן׃
אַ גאָרטנקװאַל, אַ ברונעם לעבעדיקע װאַסער. און פֿלוסן פֿון לבֿנון.
Rashi
You are a garden spring. All this refers back to, “Your arid fields,” and he praises them like a fountain which irrigates them. The allegory is: It refers to the immersions of purification which the daughters of Yisroel immerse themselves.
Rashi
And flowing streams from Levanon. From a place of cleanliness, without the murkiness of mud.