Midrash for Sanhedrin 40:18
ולבסוף לא מלך אלא על מקלו שנאמר (קהלת ב, י) זה היה חלקי מכל עמלי רב ושמואל חד אמר מקלו וחד אמר גונדו
said: Three commandments were given to Israel when they entered the land; [i] to appoint a king; [ii] to cut off the seed of Amalek; [iii] and to build themselves the chosen house [i.e. the Temple] and I do not know which of them has priority. But, when it is said: The hand upon the throne of the Lord, the Lord will have war with Amalek from generation to generation,<span class="x" onmousemove="('comment',' Ex. XVII, 16. ');"><sup>27</sup></span> we must infer that they had first to set up a king, for 'throne' implies a king, as it is written, Then Solomon sat on the throne of the Lord as king.<span class="x" onmousemove="('comment',' I Chron. XXIX, 23. ');"><sup>28</sup></span>