Torah Temimah cites Kerisos 9a.
From where do we derive shevu’as ha-eidus? The Sages taught: In all of them it says “and it was hidden,” but here it does not say “and it was hidden” — to obligate for inadvertent violation as for deliberate.
The absence of “vene’elam” on shevu’as ha-eidus distinguishes it from the other oleh ve-yored offerings and creates liability for both intentional and inadvertent violation.