President Mugabe has said he will not appoint a successor as that is not Constitutional, but a responsibility of the party's congress which convenes every five years.
The next Zanu-PF congress is due in 2019. Addressing scores of Zanu-PF supporters on the eighth leg of the Presidential Youth Interface rallies at Chipadze Stadium in Bindura on Saturday, President Mugabe said the law did not allow him to appoint his own successor.
"Ko, we never have had our Presidential system, procedures, unguided by the rules of the party. Hatina kumbofa tazviita isu kuti mumwe anoti, seni I am President now, ndoti ndoda kusiya ngana, ndoda kusiya Mai Mugabe, ndoda kusiya Emmerson (Mnangagwa), ndoda kusiya (Phelekezela) Mphoko as my successor," he said.
"It is contrary to the Constitution. I cannot do it. It is not allowed. "Constitution inoti munhu anosarudzwa kuCongress. Ini ndingava ndine candidate ehe, but anosungirwa kunge achikwikwidzana nemamwe macandidates kuCongress and I follow. I am a lawyer also, I follow the law. I follow the regulations very strictly, handidi kuzonzi ndinzi ndakasiya mukadzi wangu aaaah ayewa.
"Zvinoitwa nevamwe vari kuma French countries. Hatidaro muZanu-PF. Tine history yakaisvonaka yeparty yedu. Tinoda kuti tiitevedzere iyoyo zvakanaka."
President Mugabe also took a dig at rogue war veterans expelled from Zanu-PF who insist on commenting on party issues claiming to be speaking on behalf of VP Mnangagwa.
He said Zanu-PF would not entertain them and that those who wanted to come back knew party procedures. "Ava vakomana ava (Zimbabwe National Liberation War Veterns Association leaders) vari kupengereka hameno kuti chavari kupengerekera chii," said President Mugabe.
"Kana achinzi masupporters aVaMnangagwa vasingazivi kuti Constitution yedu yakamira sei, vanofanira kudzidziswa. It is a pity kuti they have decided to go that way, but we should not support them and it is right and only right that we should never entertain them.
"They are wrong and they have been punished by the party and we should not entertain them. Kana vave kuda kudzoka vanoziva gwara, vanoziva kokuenda to place their pleas, kuti haaa takaona zvakati hatingarambe tiri kunze tava kuda kudzoka kuparty but hatingavadaidzi isu kuti come and be associated with us," he said.
"No. It is completely wrong saka I hope vaMnangagwa you take that advice into account. Give them the languish if they want to languish in the dark where they chose to be. We do not pay them to come back."
Turning to the forthcoming elections, President Mugabe stressed the need for unity among Zanu-PF members.
He urged the party's senior leadership to learn from the Youth League's organisational capacity as shown by the huge turnouts at the ongoing Presidential Interface rallies. "Saka tiri kunanga kuma elections. Ngatirambei takadai," said President Mugabe.
"Saka ndoda kutenda vakomana ava. Zvese zvandiri kutaura vangadai vachizvizivawo. Asi vanokwanisa kuronga marallies akakura saiyoyi," he said. "Takabva kune rimwe rekuMidlands iye zvinezvi nemamwe ese atakamboita six of them. Iyi yava number eight.
"Ose anongoda kufanana, ose ane hurongwa hunoratidza kuti vanhu vanenge vapihwa discipline yakanaka. Hapana kurwa, hapana kutukana. Tinogara zvakanaka," the President said.
Vari mberi vogara pasi vari shure vomirawo, toteerera. Totererasa shoko rinenge rabva kuvatungamiri. Ndati hurongwa uhu tirambe tinahwo. Tisvike pakuzoenda kumaelections tabva tichingobva muhurongwa hwakaita seihwou.
"Macampaigns edu vakuru onai wo. Onai mufunde kubva kuvadiki vedu. Havasi vadiki ka vana. Vadiki vedu asi vava nemhuri vari kutipa chidzidzo chemberi."