Rashi's sole comment on the following 4 verses is that the expression of guilt feelings mentioned in the first three verses caused the crying in the 4th verse. We have indicated this Rashi comment using an interpolated underlined phrase. Verses Gn42-21:24 states And they [Joseph's brothers] said one to another, We are truly guilty concerning our brother, in that we saw the anguish of his soul, when he besought us, and we would not hear; therefore is this distress come upon us. And Reuben answered them, saying, Did I not speak to you, saying, Do not sin against the child; and you would not hear? therefore, behold, also his blood is required. And they knew not that Joseph understood them; for he spoke to them by an interpreter. [ and hence because of this expression of guilt] he [Joseph] turned himself away from them, and wept; and returned to them again, and talked with them, and took from them Simeon, and bound him before their eyes.

Sermonic points:The above Rashi paints the conflicting emotions in Joseph. On the one hand he was sold into slavery for 13 years because of one of his brothers. On the other hand the expression of guilt changed a possible anger into crying. Here we see how repentance can change and possible heal an emotional abusive relationship.