Is what Umar ibn al-Khattab, may Allah be pleased with him, did—taking a portion of the land that the Messenger of Allah, peace and blessings be upon him, granted to Bilal ibn al-Harith, may Allah be pleased with them both—considered a silent consensus or an act of ijtihad by the ruler?

The hadith transmitted by Al-Bayhaqi and others states that the Prophet, peace and blessings be upon him, granted Bilal ibn Al-Harith a vast tract of land for the purpose of reclaiming and cultivating it. During the caliphate of Umar, may Allah be pleased with him, when Bilal was unable to cultivate the entire land, Umar reclaimed from him what he was unable to cultivate, saying that the Prophet had not granted it to him to hoard it from the people, but to work on it. This was an ijtihad (independent juristic reasoning) by Umar, which was tacitly approved by the Companions, representing a silent consensus (ijma' sukuti). The Imam should not grant any barren land (mawat) to anyone except what can be cultivated. If the grantee is unable to cultivate it, what he was unable to cultivate should be reclaimed from him, just as Umar did with Bilal. Similar is the story of Abyad ibn Hammal, whom the Prophet, peace and blessings be upon him, granted the salt mines, but then reclaimed them when it was said that salt was like readily available water, due to the harm and hardship it would impose on Muslims.