Mishneh Torah, Sales 11:1-3
משנה תורה, הלכות מכירה י״א:א׳-ג׳
Mishneh Torah, Sales 11:1-3
Discusses asmachta and transactions made without full, binding intent. Later halakhic discussions of gambling often use this as part of the conceptual basis for why wagers can be problematic.
בַּמֶּה דְּבָרִים אֲמוּרִים בְּשֶׁקָּנָה בְּדֶרֶךְ מִן הַדְּרָכִים שֶׁקּוֹנִין בָּהֶן וַהֲרֵי יֵשׁ עָלָיו לְקַיֵּם אֶת הַתְּנַאי. אֲבָל אִם לֹא קָנָה עַתָּה וְהִתְנָה עִמּוֹ שֶׁאִם נִתְקַיֵּם הַתְּנַאי זֶה יִקְנֶה וְאִם לֹא נִתְקַיֵּם לֹא יִקְנֶה אַף עַל פִּי שֶׁנִּתְקַיֵּם הַתְּנַאי לֹא קָנָה. שֶׁזּוֹ אַסְמַכְתָּא הִיא. שֶׁהֲרֵי סָמַךְ קְנִיָּתוֹ לַעֲשׂוֹת כָּךְ וְכָךְ וְכָל אַסְמַכְתָּא אֵינָהּ קוֹנָה שֶׁהֲרֵי לֹא גָּמַר בְּלִבּוֹ לְהַקְנוֹתוֹ:
When does the above apply? When a person stated a condition and then carried out a kinyan transferring ownership of the article through one of the accepted procedures. For then, he is obligated to fulfill the condition. If, however, the person did not perform a kinyan, but merely entered into a conditional agreement stating that if this condition is fulfilled he will transfer ownership, and if it is not fulfilled he will not transfer ownership, the transfer of ownership is not effected even if the condition is fulfilled. This is considered an asmachta - i.e., he made his transfer of ownership dependent on the performance of certain deeds. An asmachta is never binding, for the person transferring ownership did not make a firm decision in his heart to transfer ownership.