Matthew Poole and continuators on Ruth 4:13

13 ¶ So Boaz took Ruth , and she was his wife; and when he went in unto her , the LORD gave her conception , and in due time she bare a son.

Which he might do, though she was a Moabite, because the Prohibition against Marrying such, is to be restrained to those who continue in the Heathenish estate, as is evident from the reason of it; Whereas Ruth as a sincere Proselyte and Convert to the God and Faith of Israel.

i. e. Had Conjugal Converse with her. See Gen. 6. 4.

i. e. Strength to Conceive and Retain Seed.