"And HaShem appeared to Avraham in the fields of Mamre, and he was sitting in the entrance of his tent, like the heat of the day"(Bereishis 18:1). What is the secret of the phrase, Avraham was sitting "like the heat of the day"? The Torah likens Avraham Avinu to the sun. That is, the kindness and goodness of his heart illuminated the entire world, like the sun. Therefore, Avraham was sitting "like the heat of the day." The verse conveys to us that Avraham positioned himself outside the entrance of his tent, seeking wayfarers to invite into his home for relief and refreshments. Avraham passionately desired to provide them with shade, cool water, and a sumptuous meal. His loving kindness for all humanity radiated with warmth and light upon the entire world like the very sun.
Avraham Avinu's loving-kindness and pleasant personality, warmed the hearts of all humankind, like the glow and warmth of the golden sun.
Envision Avraham Avinu inviting you into his tent for a meal. Notice how he speaks to you with friendliness, care, and respect. Sense how his warmth and love for all mankind fills the whole world with love, compassion, and kindness. Transpose Avraham's love for every person into your heart, and light up the world with kindness, love, and joy.
(Based on the commentary of the Kli Yakar on the Torah)
