“and go after them.” Ruth could not go with the young women, who were harvesting, but could follow after them and glean.
“touch.” A euphemism for harass, especially sexually. Ruth was an unmarried woman not protected by a father or brothers, so she was very vulnerable to being harassed and even raped. The word “touch” is used of sexual intercourse in verses such as 1 Corinthians 7:1, and it is used for “harm” in Joshua 9:19.
“and drink from that which the young men have drawn.” Although Boaz could have had a cistern somewhere around his field from which water could be drawn, it seems more likely that it would have been drawn from the well close to the gate at Bethlehem (2 Sam. 23:16) and then carried to the fields where the work was being done. In the biblical culture it was usually the women who drew water (cp. Gen. 24:11). It is possible that the men actually drew this water, or it is possible that Boaz’s fields were far enough away from the well that the men carried the water there and Boaz spoke in general terms. In any case, the water was drawn by Boaz’s servants, and water was jealously guarded in the biblical culture, particularly during the dry season, which had started by the time of the barley harvest and would last from April until late October or so. That Boaz would offer his water to Ruth shows more of his noble character and kindness towards her.