Escorting a parent after they leave one’s home, and upon going on errands:
Some write that included in the command of honoring one’s parents through entering and leaving, is to escort them outside when they leave one’s home. One should not leave them after escorting them until they have left his view. [For example, when seeing them off upon leaving one’s house one should remain outside in the area that he stopped escorting them until they are no longer in his view.] In addition, some write that one should also escort them whenever they leave to perform an errand and can use one’s help. This especially applies if they are old.
 Menoras Hamaor 9:4; Meiah Shearim17; Hisorerus Teshuvah 4 Y.D. 9; Encyclopedia Talmudit Erech Kibud Av Vaeim Vol. 26 p. 380 footnote 137
 Meiah Shearim Shaar 17