Ithiel and Ucal are presented as the two men to whom Agur spoke his words in Proverbs 30. The passage is obscure, and a marginal reading treats the words not as personal names but as part of a statement expressing weariness before God.
The names occur in the heading or opening of Agur’s sayings. Because the following verses have a tone of weariness, some interpreters prefer the alternative reading that removes the proper names.
The uncertainty arises from a different pointing of the Hebrew text. The supplied material does not establish whether Ithiel and Ucal were actual persons or whether the words belong to the alternate sentence.