One uqiyah is forty dirhams

It is narrated from Sayyiduna Sa'id bin al-Musayyib (may Allah have mercy on him) that Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) stood on the pulpit, praised and glorified Allah, and said: "Take heed! Do not go to excess in the dowries of women, for if this were a matter of honour in this world or of piety with Allah, your Prophet (peace and blessings be upon him) would have been the most deserving of it. By Allah, the dowry of none of his (peace and blessings be upon him) pure wives or daughters was raised above twelve uqiyah, which comes to four hundred and eighty dirhams, one uqiyah being forty dirhams."
Sahih chains are mutawatir (mass-transmitted) establishing the authenticity of this sermon of the Commander of the Believers, Umar bin al-Khattab (may Allah be pleased with him), and I have all the narrations on this topic compiled in a large volume (juz'), but the two Shaykhs did not record it.

It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that a man came to the Prophet (peace and blessings be upon him) and said: "I have married a woman of the Ansar for a dowry of eight uqiyah." The Messenger of Allah (peace and blessings be upon him) was astonished at this and said: "It is as though you people carve silver out of the side of this mountain (that is, such a large dowry)! Did you see her (beforehand)? For there is something (a particular defect or colouring) in the eyes of the Ansar." He said: "Yes, I have seen her." He (peace and blessings be upon him) said: "We have nothing (to give you), but we will send you on an expedition, and I hope that you will obtain some good from it." So he (peace and blessings be upon him) included him among some people setting out towards a clan of Banu Abs. The Prophet (peace and blessings be upon him) ordered a she-camel for them, on which they loaded their belongings, but it had gone only a little way when it became exhausted and sat down, and it would not get up despite the people's efforts. There was no one in that party younger than this (newly married) man, so he came to the Prophet (peace and blessings be upon him) while he (peace and blessings be upon him) was lying reclining in the mosque. He stood at his head, not wishing to wake him (peace and blessings be upon him). Then, when the Prophet (peace and blessings be upon him) woke up, he said: "O Prophet of Allah, we would like you to raise the she-camel you gave us to ride." So the Prophet of Allah (peace and blessings be upon him) gave him his right hand, took his cloak with his left hand, put it over his shoulder, and walked until he reached the she-camel. He (peace and blessings be upon him) struck it with the sole of his foot, and by the One in whose hand is the soul of Abu Hurayrah, after that the she-camel would get ahead even of the one leading it. Then they reached the enemy, who had lit fires. The Muslims surrounded them on all sides and all raised the takbir together as one man, and Allah Almighty defeated them, and some of their people were taken captive.
This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), but they did not record it with these words. Imam Muslim recorded only this much, through the hadith of Shu'bah, that a man married and the Messenger of Allah (peace and blessings be upon him) said: "Did you see her?" And its narrator Abu Isma'il is Bashir bin Salman, whom both Shaykhs used as evidence.

It is narrated from Sayyiduna Abu Hadrad al-Aslami (may Allah be pleased with him) that he came to the Prophet (peace and blessings be upon him) seeking help with his wife's dowry. He (peace and blessings be upon him) asked: "How much dowry have you fixed?" He said: "Two hundred dirhams." He (peace and blessings be upon him) said: "Even if you were carving silver out of the valley of Buthan, you would not have fixed more than this (that is, this dowry is far too much for your means)."
This hadith has a sahih (authentic) chain, but the two Shaykhs (Bukhari and Muslim) did not record it.