The author of al-Qāmūs al-Muḥīṭ states: “al-shafʿ is the opposite of witr—it means ‘even’, i.e., a pair. al-shufʿah is when you add something to what you already possess, thereby making it a pair and increasing it. A shāʾ shāfiʿ (a ‘paired’ ewe) is one that carries a fetus followed by another; it is called shāfiʿ because its offspring makes it—even as it makes the offspring—into a pair. Istashfaʿahu ilaynā means: he asked him to intercede.”
Al-Muʿjam al-Wasīṭ, published by the Academy of the Arabic Language in Egypt, says: “Shafaʿa a thing (shafʿan): he added its like to it and made it a pair. When blurred vision looks at forms, it sees them doubled. Istashfaʿa means: he sought a helper or an intercessor. al-Shafāʿi are items that come in pairs; al-shafāʿah is the speech of the intercessor; and al-shafīʿ is that which makes something single into a pair.”
Ibn al-Athīr says in al-Nihāyah: “al-Shufʿah is derived from ‘increase’, for the person exercising shufʿah adds the purchased property to what he already owns, pairing it with his holding. It is as though the property had been a single, an odd number, and then became an even pair; and the shāfiʿ is the one who turns the odd into an even … .”
From these and similar citations the meaning of istishfāʿ becomes perfectly clear: it is for one person to ask another to join him in making a request so that, by virtue of the second person’s participation, the petition is doubled—that is, the two of them become a shafʿ (a pair). On the basis of this linguistic root the juristic meaning of istishfāʿ was established: requesting people of righteousness, learning, and piety to join the Muslims in supplicating Allah during times of hardship, thereby adding their voices to those who pray and increasing the number of supplicants, which makes acceptance of the prayer more likely.
With this, we can also understand the Supreme Intercession of the Prophet ﷺ on the Day of Resurrection: by unanimous agreement of the scholars, it is the Prophet’s supplication for the people after they come to him and ask him to