Malchut without the Light is considered ‘poor’. When we pray we come as poor because without the Light we have nothing. Making a proper spiritual connection is the aspect of Tzedakah because it connects the upper Sefirot to the poor (Malchut) below and nourishes him life energy.
“אַשְׁרֵי, שֹׁמְרֵי מִשְׁפָּט; עֹשֵׂה צְדָקָה בְכָל-עֵת”
“Blessed are they who observe justice, who do righteousness (Tzedakah) at all times!”
Tzedakah has wide aspect and it should be part of our daily life and consciousness.