Leviticus 5:12

חטאת הוא IT IS A SIN-OFFERING — Here, too, the apparently redundant words intimate: if the קמץ has been taken from it and has been burnt for the purpose of (i.e. having in mind that it is) a sin-offering it is valid; if, however, this was done not for its purpose (i. e. the priest had another offering in mind when officiating) it is invalid (Sifra, Vayikra Dibbura d'Chovah, Chapter 19 9).

וֶהֱבִיאָהּ֮ אֶל־הַכֹּהֵן֒ וְקָמַ֣ץ הַכֹּהֵ֣ן ׀ מִ֠מֶּ֠נָּה מְל֨וֹא קֻמְצ֜וֹ אֶת־אַזְכָּרָתָהּ֙ וְהִקְטִ֣יר הַמִּזְבֵּ֔חָה עַ֖ל אִשֵּׁ֣י יְהֹוָ֑ה חַטָּ֖את הִֽוא׃

Then shall he bring it to the priest, and the priest shall take his handful of it, the memorial part of it, and burn it on the altar, upon the pyres of the Lord: it is a sin offering.