One day Naomi said to Ruth, “My daughter, it’s time that I found a permanent home for you, so that you will be provided for. Boaz is a close relative of ours, and he’s been very kind by letting you gather grain with his young women. Tonight, he will be winnowing barley at the threshing floor. Now do as I tell you—take a bath and put on perfume and dress in your nicest clothes. Then go to the threshing floor, but don’t let Boaz see you until he has finished eating and drinking. Be sure to notice where he lies down; then go and uncover his feet and lie down there. He will tell you what to do.” (Ruth 3:1-4)
Naomi quickly recognized that Ruth’s gleaning in the field of Boaz was about much more than a basket of grain. Boaz was a near kinsman and he was willing to show kindness to Ruth. Each time I read the book of Ruth I get the impression that Naomi was quite the matchmaker.
“I will do everything you say,” Ruth replied. So she went down to the threshing floor that night and followed the instructions of her mother-in-law. After Boaz had finished eating and drinking and was in good spirits, he lay down at the far end of the pile of grain and went to sleep. Then Ruth came quietly, uncovered his feet, and lay down. Around midnight Boaz suddenly woke up and turned over. He was surprised to find a woman lying at his feet! “Who are you?” he asked. “I am your servant Ruth,” she replied. “Spread the corner of your covering over me, for you are my family redeemer.” “The Lord bless you, my daughter!” Boaz exclaimed. “You are showing even more family loyalty now than you did before, for you have not gone after a younger man, whether rich or poor. Now don’t worry about a thing, my daughter. I will do what is necessary, for everyone in town knows you are a virtuous woman. (Ruth 3:5-11)
Some have suggested that Ruth was prompted to do something improper; yet according to the customs of that day, neither Naomi nor Ruth’s actions were wrong. According to one resource, “Ruth lay crosswise at Boaz’s feet– a position in which Eastern servants frequently sleep in the same chamber or tent with their master; and if they want a covering, custom allows them that benefit from part of the covering on their master’s bed.” 
Being an influential man of the community, Boaz most likely knew about every parcel of land in Bethlehem. He was well aware that a relative of his by the name of Elimelech had taken a lien against his inheritance many years earlier. He also knew that both Naomi and Ruth were of Elimelech’s family and that there was in the land the law of the kinsman redeemer.
There is no indication that Boaz considered Ruth’s actions as being sexual or improper. As a matter of fact, Boaz was very concerned about protecting her innocence. His surprise was not as much that there was a woman lying at his feet, but that this young beautiful woman was asking him to become her kinsman redeemer.
The Bible says, “Trust in the Lord with all your heart and lean not unto your own understanding. In all your ways acknowledge Him and He will direct your paths!” Proverbs 3:5-6