If you reflect on the two hadiths, you will find no contradiction between them. What is meant by “the utmost effort of one with little” is that which exceeds his own sufficiency, though he is not a person of abundant wealth.
His statement, “and he incurs sin by what diminishes it”: yanquṣu-hā (“diminishes it”) is the correct reading. Some may read it as yunqiṣu-hā, using the quadriliteral form, but it is from the triliteral form. It may be intransitive or transitive; indeed, it may take two objects. Allah says, “Then they have not failed you in anything” [al-Tawbah 9:4]. Here it takes two objects: the pronoun referring to “you” and “anything.” It may also be intransitive, as when one says, “The wealth diminished.” Similarly, zāda (“increased”) may be used transitively, as in, “He increased me in goodness.” Allah says, “As for those who believe, it increased them in faith” [al-Tawbah 9:124], where it takes two objects. It may likewise be intransitive, as in, “The wealth increased.”
His statement, “he incurs sin,” means: the one who gives charity.
And his statement, “by what,” means: by a charity that diminishes his own sufficiency and the sufficiency of those whom he supports.
The reason for this is that if one falls short in what is obligatory, he incurs sin. How can it be fitting for you to neglect an obligation and give voluntary charity instead? This is unfitting according to the Sacred Law, reason, and common convention. So begin first with those whom you support.
Also know that the best charity you give is that which you give to yourself and your family, for charity given to one’s family is better than charity given to someone distant, as mentioned in hadith (1). Thus, when you fulfill the obligatory maintenance of your family, you are fulfilling both an obligation and an act of charity, as is authentically established from the Prophet ﷺ that