Commentary for Kiddushin 33:12
חדא דתפשתה מרובה לא תפשתה תפשתה מועט תפשתה ועוד עבד מעבד הוה ליה למילף
But perhaps [the comparison is] with the least [sum] of 'arakin?<span class="x" onmousemove="('comment',' Five shekels, Lev. XXVII, 6.');"><sup>16</sup></span> - It is written, as the Lord thy God hath blessed thee.<span class="x" onmousemove="('comment',' V. p. 75, n. 5.');"><sup>17</sup></span> But let us learn the meaning of 'giving' from a slave: just as there, thirty, so here too thirty: [for] firstly, if you seize much, y cannot hold; if you seize little, you can hold; and moreover, one should rather deduce slave from slave? - R'Simeon deduces 'poverty' from 'poverty'.<span class="x" onmousemove="('comment',' [Or, 'he learnt on tradition (from his teacher; the deduction of) 'arakin 'poverty" (from)="" 'poverty"="" 'it="" being="" the="" rule="" that="" no="" one="" may="" draw="" a="" conclusion="" from="" qezerah="" shawah="" on="" one's="" own="" authority,="" v.="" pes.="" ');"=""><sup>18</sup></span>
Daf Shevui to Kiddushin
The second reason is obvious—better to learn from a similar context.