Ruth was a Moabite girl who married into a family of Israelite transplants living in Moab because there was a famine going on at home. When her young husband died, her mother-in-law, Naomi, decided to pull up stakes and head back for Israel where she belonged. The famine was over by then, and there was no longer anything to hold her where she was, her own husband having died about the same time that Ruth's had. She advised Ruth to stay put right there in Moab and to try to snag herself another man from among her own people.
She was a strong-willed old party, and when Ruth said she wanted to go to Israel with her, she tried to talk her out of it. Even if by some gynecological fluke she managed to produce another son for Ruth to marry, she said, by the time he was old enough, Ruth would be ready for the geriatric ward. But Ruth had a mind of her own too, besides which they'd been through a lot together, what with one thing and another, and home to her was wherever Naomi was. "Where you go, I go, and where you live, I live," Ruth told her, "and if your God is Yahweh, then my God is Yahweh too" (Ruth 2:10-17). So Naomi gave in, and when the two of them pulled in to Bethlehem, Naomi's hometown, there was a brass band to meet them at the station.
Ruth had a spring in her step and a fascinating Moabite accent, and it wasn't long before she caught the eye of a prosperous farmer named Boaz. He was a little long in the tooth, but he still knew a pretty girl when he saw one, and before long, in a fatherly kind of way, he took her under his wing. He told the hired hands not to give her any trouble. He helped her in the fields. He had her over for a meal. And when she asked him one day in her disarming Moabite way why he was being so nice to her, he said he'd heard how good she'd been to Naomi, who happened to be a distant cousin of his, and as far as he was concerned, she deserved nothing but the best.
Naomi was nobody's fool and saw which way the wind was blowing long before Ruth did. She was dead set on Ruth's making a good catch for herself, and since it was obvious she'd already hooked old Boaz whether she realized it or not, all she had to do was find the right way to reel him in. Naomi gave her instructions. As soon as Boaz had a good supper under his belt and had polished off a nightcap or two, he'd go to the barn and hit the sack. Around midnight, she said, Ruth should slip out to the barn and hit the sack too. If Boaz's feet just happened to be uncovered somehow, and if she just happened to be close enough to keep them warm, that probably wouldn't be the worst thing in the world either (Ruth 3:1-5). But she wasn't to go too far. Back in Jericho, Boaz's mother, Rahab, had had a rather seamy reputation for going too far professionally, and anything that reminded him of that might scare him off permanently.
Ruth followed her mother-in-law's advice to the letter, and it worked like a charm. Boaz was so overwhelmed that she'd pay attention to an old crock like him when there were so many young bucks running around in tight-fitting jeans that he fell for her hook, line, and sinker and, after a few legal matters were taken care of, made her his lawful wedded wife.
They had a son named Obed after a while, and Naomi came to take care of him and stayed on for the rest of her life. Then in time Obed had a son of his own named Jesse, and Jesse in turn had seven sons, the seventh of whom was named David and ended up as the greatest king Israel ever had. With Ruth for his great-grandmother and Naomi for his grandfather's nurse, it was hardly a wonder.