what Moshe did to merit seeing the burning Moshe

When Moshe sees the burning bush, he turns towards it to see what is going on.  

וַיַּ֥רְא ה׳ כִּ֣י סָ֣ר לִרְא֑וֹת  וַיִּקְרָא֩ אֵלָ֨יו אֱלֹקים מִתּ֣וֹךְ הַסְּנֶ֗ה וַיֹּ֛אמֶר מֹשֶׁ֥ה מֹשֶׁ֖ה וַיֹּ֥אמֶר הִנֵּֽנִי׃

As a result, a Hashem appears and calls to him.

What's so special about Moshe turning to see what's going on that elicits this call from Hashem to make him the leader of Klal Yisrael?  Wouldn't any of us who came across an inexplicable phenomenon, הַמַּרְאֶ֥ה הַגָּדֹ֖ל הַזֶּ֑ה מַדּ֖וּעַ לֹא־יִבְעַ֥ר הַסְּנֶֽה, come closer to take a look?

Says the Midrash:

אָמַר רַבִּי יִצְחָק, מַהוּ כִּי סָר לִרְאוֹת – אָמַר הַקָּדוֹשׁ בָּרוּךְ הוּא סָר וְזָעֵף הוּא זֶה לִרְאוֹת בְּצַעֲרָן שֶׁל יִשְׂרָאֵל בְּמִצְרַיִם,

It's not Moshe's turning his attention to look at the burning bush which the pasuk is referring to; it's referring to Moshe's having turned his attention to the suffering of his bretheren in Mitzrayim.  The words סָר לִרְאוֹת is talking about what we read in the previous chapter (2:11),  וַיִּגְדַּ֤ל מֹשֶׁה֙ וַיֵּצֵ֣א אֶל־אֶחָ֔יו וַיַּ֖רְא בְּסִבְלֹתָ֑ם.

The tnai rishon to be zocheh to see hashra'as haShechina, to be zocheh to וַיִּקְרָא֩ אֵלָ֨יו אֱלֹקים, is to first open your eyes and see the suffering and needs of your fellow Jew.