As-Salaam alaikum,

In ayat 112 of Surat Hud of the Holy Qur'an (11:112), Allah Ta'ala says:--

"Stand firm (in the straight path) as you have been commanded."

As reported in Abu Qasim al-Qushayri's 'Al-Risala al-qushayriyya fi ilm al-tasawwuf (Epistle on Sufism), Abu al-Ja'd said on the authority of Thawban, may Allah be pleased with him, the Prophet, Sallallahu alaihi Wasallam, said:--

"Be upright! Though you will never be able to do this fully. Know that the
best part of your religion is prayer, and only the [true] believer is capable
of preserving his [ritual] purity."

On this, Shaykh Abu Abd al-Rahman al-Sulami, may Allah be Merciful to him, said: I heard Abu Ali al-Shabbuwi say: 'I saw the Prophet, Sallallahu alaihi Wasallam, in a dream and I said: 'It is reported that you, Ya-Rasulullah, said that the Chapter of Hud has turned your hair turn white. What was it that made your hair turn white: the stories of the past and of the destruction of Nations?' He answered: 'No, it was [Allah's Command] ''Be Upright, as you have been commanded.''

It is said that only the greatest of men are capable of maintaining uprightness, because it means the abandonment of one's habits and departure from habitual routines and customs, while standing before Allah Most High, in full truthfulness and sincerity. This is why the Prophet, alaihi-salaat was-salaam, said 'Be upright, though you will never be able to do this fully.'

Respected 'Ulama of the Ummah said that Uprightness in one's speech means to forsake backbiting; uprightness in one's deeds means to abandon innovations in religion (bid'a); uprightness in one's good works means to avoid laxity.
May we be blessed with being upright... ameen.