Sifri: "Ki Siktzor" implies that Shikcah only applies if the owner was reaping his harvest, but not if robbers cut it down, if it was devoured by ants or if the wind or an animal broke it. ¹

Yerushalmi Pe'ah, 5:6. "Ketzircha" implies the harvest of the owner - to preclude where the laborer forgot a sheaf but the owner didn't from the Din of Shikchah; whereas "Ki Siktzor" implies the person who is harvesting - to preclude where the owner forgot the sheaf but the laborer didn't.

Sifri: "Ketzircha" implies that the harvest belongong to Hekdesh or to Nochrim is not subject to "Lo Sashuv Lekachto",

Sotah, 45: To incorporate standing corn in the Din of Shikchah, ¹ and to preclude sheaves that the wind blew into a neighbor's field and the owner subsequently forgot it.

Yerushalmi Pe'ah, 5:7: To teach us that just as Katzir is final, so too, does Shikchah only apply to sheaves that are 'final' - before taking them to the granary - to preclude, for example, where the owner initially gathers the corn to make wreaths to be worn as crowns before making them into sheaves to take to the granary.

Yerushalmi Pe'ah, 6:6: It implies that, if the sheaf is surrounded (not by "Katzir", but) by standing corn, it is not subject to "Lo Sashuv Lekachto". ¹

Rashi: It implies that, if the owner forgot (not a sheaf, but) a hay-stack of corn, he is permitted to go back for it. ¹

Sotah, 65a: It implies that it is only a sheaf that once forgotten, is permanently forgotten, but not a prize olive-tree, ² which will be remembered even after one by-passed it during harvesting. ³

Rashi: To incorporate standing corn in the Din of Shikchah.

Sotah, 45a: "ba'Sadeh" incorporates what is hidden in the ground in the Din of Shikchah.

Sotah, 5a: It includes corn that is buried in the ground in the Din of shikchah. ¹

Bava Metzi'a, 11a: Sheaves in the field are only subject to Shikchah if they are initially forgotten but not if the owner remembered them initally and only forgot them later - but not sheaves that one forgets in town, ² which are subject to Shikchah either way. ³

Rashi: It imlpies that it is only a sheaf that is behind him that is subject to Shikchah, but not one that is in front of him. ¹

Bava Metzi'a, 11a: It comes to incorporate Shikchah that one forgets in the town in the Din of Shikchah. ²

Sifri: It teaches us that it is only Shikchah if one would need to o back to collect it - to preclude where the tops of the stalks that he forgot can reach the standing corn that he did not fotget - and can be picked together with it. ³

Yerushalmi, 4:5: It implies that whatever the case, it shall go to the Ger, Yasom or Almanah ¹ - to tach us that 'Safek Leket, Leket'.

Rashi: To teach us that, even though the Mitzvah came about completely unintentionally, ¹ the owner has nevertheless earned himself a Berachah. ²

Oznayim la'Torah: The Torah writes it here, where has already worked hard reaping the produce and making it into sheaves and it is hard on him to see others taking it, and not by Pe'ah of olives and grapes in the next two Pesukim, where he has not yet done any works on them. ³

Yerushalmi Pe'ah, 4;3: Seeing as standing corn is subject to Shikchah, from which the Nochri was Patur, he is also Patur from Shikchah regarding the sheaves - to which the standing corn is compared. ¹ And consequently, he is also Patur from Leket and Pe'ah as well. ²